The treatment and subsequent recycling of wastewater is a cornerstone of the quality of life in the industrialized world. Cities, industries, and agricultural operations produce large quantities of wastewater, all of which must be treated to some degree or another before the water is suitable for recycling or discharge into streams, rivers or the oceans. In metropolitan areas, central water treatment plants or Waste Water Treatment Plants (WWTP) must treat water from a variety of sources including industrial wastewater. In many metropolitan areas industrial waste water generators are required to install and operate waste water treatment plants at their own sites before discharge into central water collection systems. At the central water collection system, industrial wastes are mixed with domestic wastewater and other untreated waste sources. These mixed wastes are then transported to the central wastewater or sewage treatment facility for final treatment before discharge. In the case of the present invention, it will be readily appreciated by WWTP operators that knowledge of the incoming waste water composition would be of great benefit in assuring the continued operation of the central facility at top efficiency.
Increasingly, the need for pure water is causing more and more municipalities to install wastewater recovery processes to recycle municipal WWTP effluent back suitable as potable drinking water or irrigation quality. The first major application in the U.S. of this sort was the Fountain Valley, Calif. Water Factory which recovers secondary treated municipal effluent using reverse osmosis. Here, as in many other examples, the recovered water is injected back into an aquifer. More and more of these installations are planned throughout the United States and the rest of the world.
One difficult aspect of treating municipal effluent is that neither the flow rates nor the mix of contaminants are constant. This is particularly true for municipal WWTP with collection systems that include a variety of industrial discharge sources in addition to the usual sanitary discharges from homes, businesses, schools, and so on. While the sanitary discharges are well characterized in terms of composition and treatability, the addition of industrial wastes means that the WWTP must plan for a wide variety of contaminants. In general, most WWTP systems cannot deal effectively with every situation. Even with excellent design and engineering, the large fluctuation in the type and quantity of contaminants reaching the WWTP often result in varying levels of effective treatment in the discharge from the WWTP. For a tertiary water recovery plant treating the effluent from the WWTP this can be particularly difficult since many contaminants are not readily removed even by processes such as reverse osmosis. In addition, certain contaminants can also foul reverse osmosis, ultrafiltration, and microfiltration membranes, causing loss of performance or membrane damage.
The instant invention provides a method whereby relevant information about the quantity and composition of industrial waste discharges can be reliably and quickly transmitted to the operators of the central WWTP. This advance notice allows the WWTP to respond to varying contaminant introductions in a far more effective manner than at present, where the first knowledge or information may come after the contaminants have already entered or even passed through the system. For WWTP entities that operate reclamation facilities downstream of the WWTP, this advance knowledge is even more valuable as it allows the reclamation facility to modify its operations as necessary to prevent damage to the process facilities. Even more important, it provides the WWTP the ability to modify its operations to prevent the introduction of dangerous, poisonous or unhealthful contaminants into the drinking water systems.
The prior art does not address the need to monitor and analyze the combined effluent of water treatment plants discharging into a common water collection system which feed into a common WWTP. Kodudula et al., U.S. Pat. No. 6,845,336, disclose a computer system linked by the Internet to various remote waste water treatment facilities which receives real-time data from the facilities. However, in the Kodukula et al. system data is transmitted from discrete, independent treatment site locations for individual analysis. Kodukula et al. does not contemplate the requirements of a WWTP processing water from a central water collection system receiving effluent simultaneously from a number of water treatments sites which are throughout the collection system. There remains a need for a system designed for WWTPs which can collect and interpret data from a number of water treatments sites as an aggregate system.
Typically industrial waste treatment systems, for example heavy metal precipitation or recovery systems often found at circuit board manufacturers, are equipped with basic instrumentation allowing the local operators to monitor the performance of the systems. In some cases, visual or audible alarms are provided, or alarm devices known as autodialers can send alarm messages to various destinations. The Sensaphone 2000, as sold by Sensaphone Inc., is an example of a device which can connect to instruments or switches and send alarms in response to various readings. While these types of devices often have a data logging function built in, they in general do not send raw information without being polled for the information and do not have any control capability.
At more sophisticated installations, the industrial waste water treatment system may be monitored and controlled by an existing in-house Supervisory Control and Data Acquisition System (SCADA). At still other installations, control of the waste water treatment system may be effected by Progammable Logic Controllers (PLC) with a standalone user interface. Both PLC and SCADA systems generally have communication systems which allow them to either send data to other systems or computers, automatically or when requested. Furthermore, many PLC and SCADA systems also have provision for remote control and access operations, allowing outside users to connect via a variety of protocols such as TCP/IP (Internet) or dial-up access. Normally such remote access is reserved for the authorized employees and operators of the industrial process being monitored and controlled.
One particular area in which the present invention provides a substantial improvement over prior art systems is the area of operational security for the process being monitored. Consider the example of an industrial facility with an important industrial waste water treatment system on site tied into the facility's primary SCADA system. If the industrial facility was asked by the municipal WWVTP to allow the municipal WWTP operators to access the SCADA system at the facility to monitor the waste water treatment system at the site, the industrial facility would potentially be opening its entire SCADA system to operators over which it has no control. In more traditional monitoring methods, it is often necessary for an outside entity (the WWTP operators in case) to have connections to the electronic control system and instruments controlling the wastewater treatment process at the industrial facility. Facility owners naturally are reluctant to allow such connections since these connections provide a potential intrusion into the control system. The present invention eliminates these potential intrusions since all data analysis and remote access to the industrial system's operating information is via an external database physically remote and not connected to the process facility being monitored. Thus the industrial facility, using the methods described in the present invention, could safely honor the municipality's request.
It is a further advantage of this invention that multiple industrial waste treatment plants can be simultaneously monitored by the WWTP operators receiving the waste discharge from the industrial waste treatment plants.
Yet another advantage of the present invention is that it allows sophisticated analytical programs to be applied to the data collected from the remote systems without impacting the processing power of the local control systems or requiring each individual industrial waste water treatment plant to add any special software routines to the existing SCADA or PLC programs. With data available from the majority of the industrial waste water treatment plants in an area discharging into a common WWTP, the WWTP has the possibility to analyze the incoming streams and predict conditions at the WWTP well in advance of actual impact.